A replicated site comparison study of cereal fields in the Lower Rhine area of Germany (Lösch et al. 1994) found that plant species diversity was higher in fields with unsprayed margins than sprayed margins. Plant diversity (Shannon index) was higher in fields with unsprayed margins (-2.1 to -2.4 vs-1). The average number of species was also higher in unsprayed margins compared to sprayed centres of fields in winter (4-10 species vs 0-2) and summer crops (3-7 species vs 1-3). By the end of the study, there were 100 species recorded within the study site (mean 44 species/field), including nine categorized as highly endangered by the red data book, which had recovered in the local area. Fields were either managed according to the regulations of the government field margins programme (5 m margins, no pesticides, limited fertilizer) or were managed conventionally with intensive pesticide and fertilizer use. Plant species diversity and floristic richness were sampled along transects within cereal fields.